Today, many digital multifunctional peripherals are introduced in general office environment. The digital multifunctional peripheral incorporates multiple functions, including a scanner function, a copy function, a print function, and a facsimile function, contains a hard disk, and is highly functionalized so as to connect to a network to operate Web browsers and Java (registered trademark) applications as well.
In this way, since the digital multifunctional peripheral is used not only as a copier, a printer, a facsimile, and the like, but also as a document filing terminal and a network terminal, it is necessary to take security measures sufficiently to unauthorized usage and data leakage.
As a method for authenticating a usage right of a user, user authentication is used that a user presents authentication information (a password or information of an IC card, or biological information such as fingerprint and an eyeball), which is collated with authentication information of a usage permitted user registered in a digital multifunctional peripheral in advance, and when coinciding with the authentication information, the user is authenticated and is allowed to use the digital multifunctional peripheral (Japanese Laid-Open Patent Publications No.2006-321063 and No.2007-44989).
In an image forming apparatus of Japanese Laid-Open Patent Publications No.2006-321063, when storing image data having been subjected to printing, the image data is stored in a file with a generated data name, and authentication information received from a user and the generated data name are registered in a main body in association with each other. Further, the generated data name is encrypted and stored in a storage medium. In addition, at the time of printing the stored image data, the encrypted data name stored in the storage medium is decrypted, and when the authentication information received from the user and the decrypted data name are registered in the main body, printing is performed.
Moreover, in an image forming apparatus of Japanese Laid-Open Patent Publications No.2007-44989, at the time of storing image data having been subjected to printing, when a user has been authenticated, the image data is stored in a box corresponding to the authenticated user. This box includes a named box specified by a user and an unnamed box whose name is not specified by a user. At the time of performing printing using stored image data, when a user has been authenticated, a list of file names of image data stored in a (named or unnamed) box corresponding to the authenticated user is displayed. Accordingly, it is possible to select desired image data from the list of file names concerning the user.
However, in a technology of Japanese Laid-Open Patent Publications No.2006-321063, authentication information (password) is requested when storing or using image data used for printing, thus posing a problem of complicating an input operation of a user.
Moreover, in a technology of Japanese Laid-Open Patent Publications No.2007-44989, if once authentication is performed for image data used for printing by a user, authentication information (password) is not requested every time, thus improving operability of a user. However, it is impossible to recognize existence of image data stored by other users, thus posing a problem that printing using image data stored by a coworker can not be performed.